内科学 支气管哮喘-陈小东【荐】.ppt

Bronchial Asthma Introduction Bronchial asthma a chronic inflammatory condition involving a variety of cells including eosinophils, mast cells, T lymphocytes, neutrophils, and epithelial cells of the airway, as well as cellular elements which gives rise to the increase of airway hyper-reactivity. Extensive changeable and reversible ventilation restriction is common Cause recurrent tachypnea, feeling of out of breath, and coughing The symptoms are more usually present and aggravated at night or early in the morning Remission might be achieved spontaneously or following treatment Epidemiology 160 million patients in the world prevalence：1%--5%，0.5-1% in china Prevalence in male is similar to that in female The onset is before 12 years of age in the majority Family history could be found in 20% patients Related to allergic rhinitis, eczema and nasal polyp Etiology The pathogenesis of asthma is complicated Affected by genetics and the environment It is a multigene disorder and closely related to atopy Most patients have prior history of eczema, allergic rhinitis, food or drug allergy, and quite a few patients have family history The formation and attack of asthma is also a consequence of the function of multiple environmental factors such as inhalation of allergens, respiratory tract virus infection, and coldness Etiology １．Genetic factors: multigene inheritance heritability 70-80% ２．Predisposing factors: air pollution 1）?? inhalants：dust mites、pollen 2）?? infections 3）?? food 4）?? change of weather 5）?? mental factors 6）?? exercise 7）?? drugs 8）?? menstruation, pregnacy Pathogenic mechanism Asthma is Characteristic of hyper-reactivity of the airway Chronic （allergic） inflammation is the basic lesion of asthma Allergic inflammation Investigations have shown that allergic reactions like asthma are mediated by Th2 cells. There is an increase or predominance of Th2 or its cytokines. The r